【作者】 张海；

【导师】 曾葆青；

【作者基本信息】 电子科技大学 ， 物理电子学， 2013， 博士

【摘要】 现代电子信息技术飞速发展，新型材料的不断涌现对材料介电特性的研究提出了愈来愈迫切的需求。电介质材料特性的研究和测量是现代基础科学研究中的重要组成部分，也广泛应用在电子、通信、生物、医疗、能源等各个工程领域。研究设计制造介质介电常数测试系统是材料介电特性研究中的关键一环。本文就基于新型耦合器的宽频多点复介电常数测试系统的设计和实现以及氧化石墨烯材料的介电特性测试进行了研究探讨，主要完成了以下几点理论与实验技术上的工作与创新：1)在测试原理研究上，从电磁场场理论出发，依据谐振腔微扰法复介电常数测试理论，系统地推导了介质含有损耗情形下的复介电常数微扰法理论计算公式，并将其具体应用在本文采用TE011模式圆柱谐振腔中；从微波网络模型出发，根据谐振腔二端口网络等效电路模型，将其推广至单端口谐振腔体系，系统地推导基于|S11|谐振曲线的半功率点分贝值的精确公式，进而获取单端口反射式谐振系统的品质因数。利用CST仿真软件，对单端口谐振系统进行三维电磁模拟，通过模拟的|S11|参数信息和场分布信息对公式进行验证。2)根据谐振腔系统耦合理论，通过矢量网络分析仪获取S11的相位信息，研发了判断谐振系统耦合状态的算法，在基于矢量网络分析仪的谐振系统测试中可以迅速、便捷的判断耦合状态，得到谐振系统的耦合系数，进而可以获取复介电常数测试所需要的谐振腔本征品质因数。3)针对谐振腔微扰法复介电常数测试系统中的模式干扰问题，设计研制新型结构的耦合器。新型耦合器结构简单，成本低廉，调谐便捷。在无需外加模式抑制辅助结构情形下，实现了圆柱腔谐振系统在宽频多点上电磁信号有效耦合，同时干扰模式得到有效抑制，在测试频点附近的有效带宽内保证纯净单一的TE011模式。另一方面运用CST三维电磁仿真软件，对谐振腔及其耦合器设计进行模拟验证，观察在测量频点附近有效测试带宽内的模式分布及谐振曲线。4)将基于新型耦合器的复介电常数测试系统的三维电磁设计，谐振腔体、耦合器以及升降系统的机械结构设计，实验测试数据传输和计算三部分集成在以Visual2005编制的界面框架内，完成了从最初电磁设计到机械加工，再到实验测试的整个系统流程。5)根据理论模型设计加工了基于新型耦合器的TE011圆柱谐振腔微扰法复介电常数测试系统，将谐振腔、耦合器、矢量网络分析仪、机械升降系统连接构建了复介电常数测量系统，制定合理的测试流程，制备了聚乙烯、尼龙6、有机玻璃、聚四氟乙烯等标准测试样品，判读谐振系统的振荡模式，测量谐振系统的特性参数，分析影响测试精度的主要因素。6)采用改进的Hummers法制备了氧化石墨烯测试样品，运用本文基于新型耦合器的复介电常数测试系统对其进行了宽频多点的复介电常数测试。更多还原

【Abstract】 With the rapid developing of the modern electronic information technology, theresearch and measurement of dielectric material plays an important role in the researchof basic science, and is also widely applied in the electronics, communications,biotechnology, medical treatment and energy engineering. The design and analysis ofdielectric permittivity test system is the key role in the research of the material dielectricproperties. In this paper, based on the new coupler the design of broadband multi-pointcomplex permittivity test system has been researched and dielectric properties of thegraphene oxide have been measured. The following several theoretical and experimentalresults which bring forth new ideas and innovation have been completed:1) From the theory of the electromagnetic field, the formula of the dielectric losscase complex permittivity perturbation method based on cavity perturbation theory hasbeen derived, and applied in the TE011mode cylindrical cavity. From the network modelof two-port network equivalent circuit model, we extend it to the single-port resonatorsystem, and systematically derive the precise formulas based on S11half-power pointvalue. Then we can obtain the quality factor of the resonant system. Throughthree-dimensional electromagnetic simulation using CST software, the formula isverified by the simulated S parameter and field distribution.2) According to the couple theory of the cavity system, the algorithm to judge thecouple state of the resonant system has been proposed by S11phase information. Thecouple state of the system can be quickly, conveniently judged based on the networkanalyzer, and get the coupling coefficient of the system. Then the intrinsic quality factorof the system can be got.3) For the resonant cavity mode interference problems, the design and developmentof the novel coupler has been proposed. The novel coupler has simple stucture and islow cost and convenient tuning. In the case of no external structure, the effectivecoupling of the electromagnetic signal of a high-speed multi-point in the resonancesystem can be achieved, at the same time interference mode can be effectivelysuppressed in the test frequency. The cavity coupler have been simulated and validated through CST software in the broadband multi-point frequencies.4)3D electromagnetic design, mechanical structure design, experimental test, datatransmission and computing interface have been integrated within the framework of theVisual2005, which include the cavity, couplers and lift system. The soft can completethe entire system flow from the initial electromagnetic design to the mechanicalprocessing, and experimental testing.5) Based on the theoretical model we have constructed the TE011cylindrical cavitycomplex permittivity test system by the perturbation method, which include the cavity,coupler, vector network analyzer, mechanical lifting system. We have developed areasonable test process, and build standard test samples. The main factors whichpossibly affect the test system accuracy have been analyzed.6) The graphene oxide test samples have been prepared by the way of the improvedHummer method, the complex permittivity of graphene oxide has been measured inbroadband multi-point frequencies.更多还原